In July 1863, Union forces Major General Quincy Gillmore’s Army of the South landed on Morris Island outside Charleston, South Carolina. Gillmore’s objective was to take control of Charleston Harbor and eventually, Charleston itself. Charleston and vicinity was heavily defended, including Battery Wagner on Morris Island, artillery emplacements on James and Sullivan’s Islands, and Fort Sumter in the harbor. After two unsuccessful attempts to capture Battery Wagner,Gilmore changed tactics and opted to abandon assaults in favor of siege tactics.

Gillmore decided to use long range rifled heavy artillery to reduce Fort Sumter, a tactic that had proved successful at Fort Pulaski, Georgia in April of 1862. Gilmore had several pieces of heavy artillery, as well as mortars, to shell not only Fort Sumter, but also other Confederate defensive positions and the city of Charleston itself.

To that end, Gillmore instructed Colonel Edward W. Serrell of the 1st New York Engineers to search for a location in the swamps and salt marshes between James and Morris Islands suitable for the construction of a battery from which long range artillery could fire on the city. Gilmore carefully scouted various locations and found one about 7900 yards from Charleston that appeared to be suitable for building a battery capable of holding a large rifled gun.

With assistance from the 7th New Hampshire Infantry, the engineers went to work. To construct the battery’s parapet, pilings were driven into the mud, and a platform of log crossbeams was attached to the pilings. This platform was covered with 13,000 sand bags hand carried across a 1700 foot wooden causeway by the men of the 7th New Hampshire. After completing the parapet, a wooden platform was constructed for the gun itself that was detached from the parapet. The two sections essentially floated on the surface of the marsh. On August 17th, an eight inch Parrot rifle and carriage weighing about 24,000 pounds was successfully transported to the site and mounted in place in what was called the Marsh Battery. It was a remarkable engineering accomplishment under difficult conditions. The men named the huge gun the “Swamp Angel”.

Gillmore selected Lieutenant Charles Selmer and his detachment of the 11th Maine Infantry to operate the Swamp Angel. Although Selmer was in the infantry, he had served nine years in artillery in the regular army before the war. The 11th Maine was serving in Fernandina, Florida, when Gillmore detached Selmer’s unit for duty in a mortar battery before assigning him to command of the Swamp Angel.

With the Swamp Angel ready for action, Gillmore sent a note to the Confederate commanding officer, General P.G.T. Beauregard, demanding the evacuation of Fort Sumter and Morris Island. If the Confederates refused to comply, the Swamp Angel would open fire on Charleston.

Not surprisingly, the demand was refused. At 1:30 A.M. on August 22nd, the Swamp Angel opened fire on Charleston. In all, 16 shells were fired into the city in the early morning hours; some were conventional artillery shells, and some contained an incendiary mixture called Greek Fire.

Beauregard was outraged that Gillmore shelled the city, and let him know in no uncertain terms. The Union general was unmoved. “Existing circumstances furnished a full justification for this step [shelling the city itself]” he wrote after the war. “Charleston had been besieged for seven weeks, was occupied by the enemy’s troops and batteries, gunboats had been built and were then building along its waterfront, and the avenue of escape for non combatants was open and undisputed”. However, he agreed to suspend firing for one day to allow civilians to evacuate.

On the evening of the 23rd, the Swamp Angel resumed shelling Charleston with the Greek Fire incendiary shells. Six of these shells exploded in the gun, weakening it. When the gun crew fired the 20th shot of the evening, the breech exploded, opening a large gap in the gun tube, and throwing the gun onto the parapet. After 36 shots, the Swamp Angel was finished.

Gillmore did not install another rifled gun in the Marsh Battery, but in September a pair of 10 inch seacoast mortars were placed there to fire on James Island.

After the war, the Swamp Angel was sold as scrap iron and sent to Trenton, New Jersey, where it was to be melted down. However, it was recognized as the famous weapon from Charleston, and saved from the furnace. The Swamp Angel was placed on display in Trenton. It’s still there today, in the city’s Cadwalader Park.

Sources:

“The Army Before Charleston in 1863″ By Quincy A. Gillmore. In Battles and Leaders of the Civil War, Vol. 4. (1988)

“The Swamp Angel” by William S. Stryker. In Battles and Leaders of the Civil War, Volume 4.